The age-related alterations of the expression of type I collagen and collagen-binding heat shock protein

Research Project

Project/Area Number	04836008
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	老化(加齢)
Research Institution	Nagoya University
Principal Investigator	SAGA Shinsuke Nagoya University, School of Medicine, associated Professor, 医学部, 助教授 (40144141)
Co-Investigator(Kenkyū-buntansha)	MIYAISHI Osamu Aichi Medical University, Institute for Medical Science of Aging, assistant rese, 加齢医科学研究所, 助手 (60229797)
Project Period (FY)	1992 – 1993
Project Status	Completed (Fiscal Year 1993)
Budget Amount *help	¥1,800,000 (Direct Cost: ¥1,800,000) Fiscal Year 1993: ¥700,000 (Direct Cost: ¥700,000) Fiscal Year 1992: ¥1,100,000 (Direct Cost: ¥1,100,000)
Keywords	aging / stress protein / collagen-binding / HSP47 / fibroblasts / heat-response / procollagens / molecular chaperone / 熱ショック蛋白質
Research Abstract	Collagen-binding heat shock protein of molecular weight 47,000(HSP47)is a resident protein in the endoplasmic reticulum(ER), and assumed to play a specific role on the processing of procollagen molecules, as a molecular chaperon specific for procollagen molecules. In this study, we investigated the age-related alteration of the heat response of HSP47 expression in cultured murine and human fibroblasts. In the cells in low population doubling level(PDL), HSP47 expression was more inducible by heat treatment in those derived from young mice and persons than from old ones. On the other hand, the cells in high PDL showed very low heat response of HSP47 expression regardless of the age of donors. Northern blot analysis of HSP47m-RNA indicated that the age related attenuation of HSP47 expression was regulated by transcriprional mechanisms. Furthemore, immunofluorescent analysis using a monoclonal antibody against amino-terminal propeptide of type I procollagen revealed that much more procollagen molecules retained in ER lumen of the cells from old persons than in the cells from young persons. The retention of procollagen molecules in ER was much more prominent in heat-treated cells, indicating the possibility that the decrease of heat response of HSP47 in the cells from old persons can explain the retention of procollagen molecules in ER lumen.